Conveyor mechanism



Ja'n. 17, 1956 E. A. sMlTH CONVEYOR MECHANISM 2 Sheets-Sheet l FiledAug. 24, 1951 AIT s@ Inventor: Ernest A. Smith His Attorney.

E. A. SMITH CONVEYOR MECHANISM Jan. 17, 1956 2 Sheets-Sheet 2 Filed Aug.24, 1951 Hts Att orneg.

n inventor. Ernest A. Smith bQ/-Aw-Wf u TN wsa United States Patent OCONVEYOR MECHANISM Ernest A. Smith, Schenectady, N. Y., assignor toGeneral Electric Company, a corporation of New York Application August24, 1951, Serial No. 243,506

2 Claims. (Cl. 198-219) This invention relates to conveyor mechanisms,and more particularly to conveyor mechanisms for use in conveying workthrough heat-treating furnaces and the like.

An object of my invention is to provide a mechanism suitable for thesimultaneous conveyance of work-pieces of assorted sizes and shapes.

Another object of the invention is to provide a mechanism which willconvey such assorted pieces and at the same time maintain allwork-pieces in the alignment in which they are placed initially on themechanism.

A further object of the invention is to provide a conveyor mechanismwhich handles work-pieces of assorted sizes and shapes and maintainsthem in alignment, and which is suitable for use at high temperatures ina furnace or the like.

A still further object of the invention is the provision of a conveyormechanism suitable for use in a furnace which provides maximum exposureof the pieces being conveyed to the heat of the furnace.

Other objects and advantages of my invention will'become apparent fromthe subsequent description of a preferred embodiment thereof, while thescope of the invention is defined in the appended claims.

In one form or" my conveyor mechanism, I provide 'fixed means forming asubstantially horizontal support, and conveying means for raisingvertically a work-piece resting on the horizontal xed support, movingthe work-piece a predetermined distance substantially parallel with thehorizontal support and then lowering the work-piece vertically onto thehorizontal support again. The conveying means comprises movable supportmeans, a rotatable cam, means operated by the cam for raising andlowering the movable support means vertically, and separate meansoperated by the cam for operating the movable support means back andforth horizontally.

For a clearer and more complete understanding of my invention, referenceshould be had to the accompanying drawing, in which Fig. 1 is a sideelevational view having two small portions in section of a furnaceembodying the conveyor mechanism of this invention; Fig. 2 is anenlarged partial end view along 2-2 of the furnace of Fig. 1 with thewalls of an auxiliary enclosure near the bottom thereof in section; Fig.3 is an enlarged partial view showing a part of the same side of thefurnace as Fig. l with a portion of the furnace in section and with acover plate removed from the auxiliary enclosure; Fig. 4 is an enlargedpartial top view of the furnace in section, along the line 4-4 of Fig.3; Fig. 5 is a diagram illustrating the operation of my conveyormechanism; Fig. 6 is an enlarged partial View in perspective showingsome of the construction details of the conveyor mechanism; Fig. 7 is anenlarged partial view in section along the line 7-7 of Fig. 3illustrating other details of the conveyor mechanism; and Fig. 8 is anenlarged fragmentary view partially in section of a part of the conveyormechanism showing the details thereof.

There is illustrated in Fig. 1 of the drawing an elonrice gated furnace10 of the continuous type customarily used for the heat-treating ofsmall metal parts. The furnace includes an outer' metal casing 11enclosing a long, rectangular heating chamber 12 on the ends and on foursides (i. e., the top, bottom and two vertical sides). Inside the outercasing 11 is located a layer 13 of thermal insulating material whichalso surrounds the heating chamber 12. Externally of the casing 11, thefurnace may be provided with vertical supports 16 upon which the furnacerests. As shown in Fig. 1, the furnace 10 is provided with a door 14 andan operating mechanism 14a therefor on the left end of the furnace whichprovides for the admission into the furnace of pieces to be heated. Onthe opposite or right end of the furnace as illustrated in Fig. 1, itincludes an exit door 15 and an operating mechanism 15a for this door.The furnace may be heated by any conventional means. (not shown), suchas electric heating units, gas arnes or oil flames.

The conveyor mechanism for the furnace which l have designated generallyby the numeral 17 extends entirely through the furnace and is housed inpart within the furnace chamber 12 and in part within an auxiliaryenclosure 18 which extends the length of the furnace below the lowerwall of the heating chamber. The supplementary enclosure 18 which isrectangular in cross section is formed by four walls 19 of metal plusend portions 19ur of the same material, as seen in Figs. l and 2 of thedrawing. The side walls of supplementary enclosure 18, as shown in Figs.1 and 2, are provided with a plurality of openings which are covered bycover plates 2l); these cover plates may be removed to expose portionsof the conveyor mechanism.

As illustrated in the drawing, particularly in Figs. 1 4 and 7, theconveyor mechanism includes a plurality of fixed support members 21arranged in four rows .which provide a substantially horizontal supportextending longitudinally through the heating chamber 12 of the furnace.The support members 21 rest on pillars 22 of insulating material whichextend upwardly from the insulating material 13 on the oor of theheating chamber, as seen best in Figs. l, 3 and 7. The support members21 are preferably formed of a metal with good heat resisting qualities,such as alloy steel, and may be in the form of channels in accordancewith Figs. 2 and 7. Portions of the supporting members 21 extendingbeyond the left end of the furnace may be bolted to the outside of thefurnace enclosure by means of nuts and bolts 24 and brackets 25, asshown best in Fig. 2. This external portion of the iixed support meansalso includes loading guides 76 along the sides of the two outermostmembers 21. The xed support members 21 within the heating chamber,however, `are preferably provided at each end with a downwardly disposedprojection 26, as seen best n Figs. 3 and 7. Each of the projections 26on the fixed members on the outer two rows has a base portion 27 havinga plurality of depending projections 78 fitting loosely over a portionof a pillar 22. These depending projections are positioned alongportions of the end and side surfaces of the pillars and in grooves 77which extend longitudinally of the furnace across the upper surfaces ofpillars 22. The fixed support members 21 making up the center two rowsmay have adjacent ends joined by a cross piece 79 (Figs. 4 and 7) ifdesired so that a common supporting base 27 is provided for the ends oftwo such members. This arrangement, as will be readily understood,provides for expansion and contraction of iixed support members 21 asthe temperature in the heating chamber is increased and decreased.

The conveying portion of the conveyor mechanism con".- prises movablesupport means including a plurality of longitudinally disposed members2S which are positioned in pairs between .the spaced rows of fixedsupport mem? the endscf two pairs ofmembers 28 and is provided with.

a pair of upward' projections. 36 (Figs. 2, 4' and. 7),. to.

retain the members ZE in position. MembersfZ. areloosery ly supported onarms Sand as. shown in Figs. 3,4. and 7 each pair of members 23 is.provided near each. end with a depending cross piece 32 to maintainmembers. 2h in the proper position onarms 311i and at the same timeallow for expansion and contraction of. members 23.

Each of thev members 291 is .movably supported uponv a carriage which isdesignated generally by the numeral. 33; This carriage is hest seedi'n.Figs. 2, 3 and4 @particularly the latter ligure. As.. shown in thedrawing, the carriage comprises. two sections 34 and 35. for convenienceof. as.` sembl'y. However, it. will be understood that. any number ofsections, one, two or mor.e,. may be used depending upon.. the length ofthe furnace. andthe. maximum size section which can. be handled.conveniently. As shown` particularly in Fig. 6 each of the sections ofthe: carriage is formed ofchannel members alongthe sides and ends, withadditionall cross members 3'7 being provided asY needed for rigidity ofthe carriage and to provide supporting means for the members 29. It willbe. readily understood that the sections of the carriage. 33 may bebraced in any conventional manner such` as by diagonal channel members,if desired, to make. certain. that the carriageis rigid. As illustrated,the sections 34 and 35. of the carriage are joined by means of astructure comprising. suitablel channel members 39 and a nut and bolt.4.6.

The carriage 33 is supported on a plurality of substantiallyhorizontally disposed levers 41 which are atixed in pairs to aplural-ityl of transverse shaftsv` 42. Each of they levers 41 isprovided with a roller 43 on the free endI thereof so that the shafts 42may bey turned, clockwise, as seen in Fig. 6, to raise the carriage, andcountercloclcwise to lower it again. Certain ofthe. rollers 43`areprovided with flanges 44 to maintain alignment of the. carriage,while the various side structural. members 36- of the car.- riage may,if d'esired,.be provided with bearing blocks. 45 for engagement withthe. rollers. The shafts i2- ma-y be journaled in suitable structuralmembers such as angle members 46 (see Fig.. 1:),

.Eachy of the shafts d2. is provided on one end with an upwardlydisposedlever. or rocker arm` 23. The rocker arms 23 are rigidly securedto. their respective shafts 42 and are positioned in substantially'parallel relation with each other in order to provide. for. thesimultaneous. operation of all of the, rocker arms. Connecting the,rocker arms 23varea plurality of connecting or tie rodsv 47 having.turnbuckles 4S.. for adjusting the lengths thereof. As illustrated inFig. 6, the shaft 42. at one end of the carriage is provided a longerrocker arm. 23: having an extension 49; a tension spring 50' isconnected between extension 49 and a fixed support such as 51. Thespring 50 tends t rotate rocker arms 23 and all the shafts 2in theclockwise direction, as will be readily apparent from the drawing.Thepurpose of thisL arrangement is explained subsequently.

In order to operate they conveyor mechanism 17 in the desired manner,there is provided a cam mechanism which includes a cam 62 mounted on ashaft 72 and a pair of camv followers 63 and 6ft mounted respectively onlevers 63a and 64a, and disposed approximately 90 apart about the axisof the shaft 72. As shown in Fig. 6, cam follower 63 is connectedthrough its lever 63a to an extension 80 of one. of shafts. 42, andsince all the shafts- 42 are connected together through rocker arms 23and tie rods 47 on. the back side of the mechanism, cam follower 63operates. all ofthe shafts 42. The. cam 62 is arranged so that when. camfollower 63 is in the up position illusof; to section 34' ofthecarriage. 33.

trated in Fig. 6, shafts 42 maintain all levers 41 in a substantially'horizontal' position as illustrated andA this maintains carriage 33 in alowered position. The cam 62 may be rotated continuously by means of agear speed reducer and a suitable driving means such as an electricmotor 66.

As illustrated, the cam 62 comprises two portions, one portion havinginner and outer cylindrical surfaces concentrically disposedl withrespect to.'l the axis of rotation of the cam. to form a passagewayextending. over a sector of approximately 90). and the other. portionhavingv si'milarly disposed inner and outer cylindrical surfaces forminga passageway extendingover a sector'of approximately 90 diametricallyopposite from the first portion. The inner and outer surfaces ofthefirst' portion are of a different radius than the corresponding innerand outer surfaces of the second portion, and, of course, surfaces jointhe inner and outer surfaces of. the. first portion. with thecorresponding surfaces of the second portion to form a continuouspassageway around the axis of rotation ofthe cam.

lf. the cam 62 is rotated counter-clockwise from the positionillustrated' in Fig, 6', cam follower 63 is depressed and moved' awayfrom cam shaft 72 which causes all'. of

cam rotation cam. follower 64' maintains its initial' radialposition,Vi. e.,v it does not move awayy from shaft 72'.

As rotation of the cam 62 is continued counterclockwise beyond the first90-d'egree sector, the cam follower 63 rides on the portion 67' ofl thecam at a constant dis.- tance from the camshaft 72, and carriage 33 isthereby maintained in the raised position for another approximately 90'degrees. During this second 90-de'gree interval, the cam follower 6.4 ismoved away from the cam shaft. to pivot counterclockwise a shaft 63 towhich. its lever 64a is connected and operate a linkage to which theshaft 68 is connected. This linkage includes a downv wardl'y disposedlever or rocker arm 69 on the other end of shaft 68 which is connectedthrough al connecting rod 70', having a turnbuckle 71 for adjusting thelength there.-

As. cam follower. 64 is pivoted countercl'ockwise away from the camshaft 72' during the second approximately 90-d'egree interval of camrotation,l lever 6:9 is also pivoted counterclockwise which through tierod'70 pulls carriage 33 tothe right..

Duringy a third approximately -degree sector on the cam 62,. thefollower 63 returns counterclockwise to its initial position adjacentcam shaft 72 while cam follower 64 remains turned to its extremecounterclockwise position. This lowersthe carriage again whilemaintaining. it at its extreme right position. Then,v during the, fourthand final approximately 9'O-degree sector on thev cam,y follower 63 ismaintained in its up position sothat the. carriage remains down, whilefollower 64 moves clockwise and moves carriage 33 back to. the leftagain to the starting point.

As will be readily understood, this action produces motion ofv carriage33 which can be illustrated. schematically by the diagramof'Fig. 5. inwhich the upwardly pointed arrow along the left side represents thefirst approximately oneuquarter of arevolution. of. cam 62, thehorizontal arrow to the right represents. the. second portion of theVcam rotation, the. downwardly pointed. arrow on the right siderepresents the third. portion of the cam rotation, and the horizontalarrow pointed to. the: left at the bottom. of the rectangle represents.the final. sectionfof a cam revolution which returns the carriage toitsstarting point. Continued: rotation of the. cam repeats this cycle. Itwill beunderstoodthat the 90'-degree, divisions of a complete camvrevolution. used; herein for purposes of. illustration. are not'critical and that one such revolution/orcycle'may be sepa rated intoother than 90-degree portions if desired.

As carriage 33 is moved, the support members 29, which are rigidlysupported on the carriage, cause the movable support members 28 to bemoved through the same cycle. The support members 29 and the movablesupport members 28 are so dimensioned, and the members 29 are soadjusted, that at the starting point of the upward vertical motion theupper surfaces of the movable support members 28 are just below theupper surfaces of fixed support members 21 as illustrated in Figs. 2 and7. During the upward substantially vertical motion of the carriage andmovable support members, the upper surfaces of movable support members28 rise above the fixed support members 21. During the second portion ofthe cycle, the movable support members move horizontally parallel to thefixed support members; during the third portion, they are lowered againso that their upper surfaces are again below the upper surfaces ofmembers 2l; and during the fourth portion, they return horizontally totheir starting point. It will be readily understood, therefore, that ifwork-pieces such as are illustrated by the dashed lines 35 in Figs. 2and 7 are placed across pairs of fixed support members 2l on oppositesides of a parallel row of movable support members, they will be pickedup substantially vertically by the motion of the movable supportmembers, moved horizontally, and again lowered on to the fixed supportmembers, and that this operation may be continued until the work-pieceshave moved completely through the furnace.

In order to adjust the support members 29 during assembly so that thelower position of movable support members 28 is below fixed supportmembers 21 and the upper position is above the fixed support members, anadjustment mechanism may be provided for support members 29 and oneadjustment mechanism suitable for this purpose is illustrated in Figs. 6and 8 of the drawing. This mechanism comprises a pair of substantiallysquare pieces of metal 73 positioned respectively above and belowcarriage 33 with four set screws 74 being provided for each member 73 tosecure it to vertical support member 29. A depending member 81 issecured to the lower clamp member 73 in a suitable manner, and portion81 is provided with a set screw 75 by means of which vertical supportmember 29 can be adjusted vertically.

The tension spring 50 assists cam follower 63 in raising the carriage inorder to lessen the stress on this cam follower. Spring 50 is providedwith sufficient initial stress that it supports most of the weight ofthe carriage so that cam follower 63 need supply only a small portion ofthe necessary lifting force in order to operate the carriage in themanner explained above.

It will be readily apparent from the foregoing that my inventionprovides a walking beam conveyor mechanism which is suitable for usewith work-pieces of a variety of sizes and shapes. Moreover, since allmotions are substantially rectilinear, the conveyor mechanism will movepieces of any size and shape which can be accommodated in the heatingchamber while maintaining their alignment the same as when they areinitially placed on the conveyor. In this connection, it will beunderstood that the tie rod '70 should be made suiiiciently long thatany deviation from rectilinear motion produced thereby when the carriageis raised is negligible. in addition to the above-mentioned advantages,this conveyor mechanism provides for the exposure of almost all of thesurface of the work-pieces being heated to the furnace atmosphere whichpromotes uniform heating.

lIn one typical installation in which my conveyor mechanism was used inwhich the furnace was approximately 32 feet long, the fixed supportmembers 21 on opposite sides of a double row of movable support memberswere spaced approximately 3 inches apart. in this same mechanism, themovable support members had a vertical motion of 2 inches and ahorizontal motion of 3 inches. It will be understood, however, that thedimensions may be varied to suit a particular installation. Othermodifications may also be made without departing from my invention, andI therefore intend to cover, by the appended claims, any modificationswhich fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. A conveyor mechanism comprising fixed means providing a substantiallyhorizontal support, movable support means for raising a work-piece fromsaid fixed support, moving it a predetermined distance substantiallyparallel with said xed support and lowering it on to said fixed supportagain, a carriage movably supporting said movable support means, aplurality of levers supporting said carriage, a plurality of shafts towhich said levers are connected, a rotatable cam, said cam comprising afirst cylindrical surface concentrically disposed with respect to theaxis of rotation of said cam and extending over a sector ofapproximately a second cylindrical surface concentrically disposed withrespect to the axis of rotation of said cam and extending over a sectorof approximately 90 diametrically opposite from said first surface, saidsecond cylindrical surface being of a different radius than said firstcylindrical surface, and surfaces connecting said first and secondcylindrical surfaces to form a continuous cam surface extending aroundthe axis of rotation of said cam, a first cam follower engaging said camsurface to operate said shafts and the levers thereon to raise and lowersaid carriage and said movable support means, a second cam followerengaging said cam surface approximately 90 from said first cam follower,means for urging said first and second cam followers into engagementwith said cam surface, and a linkage connecting said second cam followerwith said carriage for moving said carriage and said movable supportmeans horizontally.

2. A conveyor mechanism comprising fixed means providing a substantiallyhorizontal support, movable support means for raising a work-piece fromsaid fixed support, moving it a predetermined distance substantiallyparallel with said fixed support and lowering it on to said fixedsupport again, a carriage movably supporting said movable support means,a plurality of levers supporting said carriage, a plurality of shafts towhich said levers are connected, a rotatable cam, said cam comprising afirst portion having inner and outer cylindrical surfaces concentricallydisposed with respect to the axis of rotation of said cam and extendingto form a passageway over a sector of approximately 90, a second portiondiametrically opposite from said first portion and having inner andouter cylindrical surfaces concentrically disposed with respect to theaxis of rotation of said cam and extending to form a passageway over asector of approximately 90, the inner and outer surfaces of said firstportion being of a different radius than the corresponding inner andouter surfaces of said second portion, and surfaces j'oining the innerand outer surfaces of said first portion with the corresponding innerand outer surfaces of said second portion to form a continuouspassageway extending around the axis of rotation of said cam, a firstcam follower cooperating with said continuous passageway to operate saidshafts and the levers thereon to raise and lower said carriage and saidmovable support means, a second cam follower cooperating with saidcontinuous passageway approximately 90 from said first cam follower, anda linkage connecting said second cam follower with said carriage formoving said carriage and said movable support means horizontally.

References Cited in the le of this patent UNITED STATES PATENTS1,753,868 Ratliif Apr. 8, 1930 2,141,470 Harry Dec. 27, 1938 2,580,114Marvin et al Dec. 25, 1951 2,615,558 Reed Oct. 28, 1952

